Non-pneumatic wheel constructions and their benefits are described in e.g., U.S. Pat. Nos. 6,769,465; 6,994,134; 7,013,939; and 7,201,194. Some non-pneumatic tire constructions propose incorporating a shear band, embodiments of which are described in e.g., U.S. Pat. Nos. 6,769,465 and 7,201,194, which are incorporated herein by reference. Such non-pneumatic tires provide advantages in tire performance without relying upon a gas inflation pressure for support of the loads applied to the tire.
In one example of a non-pneumatic wheel, a compliant band with a ground contacting portion can be connected with a plurality of web elements extending radially from a center element or hub. For certain constructions, such non-pneumatic wheel may be formed by open cast molding in which a material such as e.g., polyurethane is poured into a mold that forms all or part of the non-pneumatic tire. Reinforcements in various parts of the non-pneumatic wheel may be molded in place. For example, one or more inextensible reinforcements such as cords may be molded in place in the compliant band.
The molds used to cast such non-pneumatic wheel constructions are a substantial part of the overall expense of manufacturing. Multiple, intricate features must be used to mold e.g., the individual web elements that extend between the hub and compliant band. Typically, the molds are carefully machined from metal having a high thermal conductivity such as e.g., aluminum.
The hub is used to connect the non-pneumatic wheel with a vehicle. The hub may be connected directly to the vehicle or may be connected through another component such as a wheel center. A variety of different constructions or configurations may be used for the hub, which may be constructed in whole or in part from one or more metals. Because of the associated expense of creating the molds, a requirement of different molds for different hub configurations is undesirable.
Accordingly, a method and apparatus for molding non-pneumatic wheels would be useful. More particularly, a method and apparatus that allows use of the same mold for manufacturing non-pneumatic wheels with different hub configurations would be particularly beneficial.